Engine off balance
Fleet Owner
Joined: Oct 2005
Posts: 20,789
Likes: 1,753
From: Kentucky
A 1996 model year 5L engine in an OBS Ford uses a distributor. Same for the other V8s and 4.9L engine used in these trucks.
Thread Starter
|
Freshman User
Joined: Sep 2014
Posts: 39
Likes: 0
Well I think I figured it out. I checked my timing and when I did, I couldn’t see the timing marks at all. I have the Innova inductive light so I put the clamp around the #1 spark wire and connected the leads to the battery. I kept seeing a line on the ring so to be sure I marked that line with soapstone (the line I saw was just a scratch). Sure enough, that was the mark I was seeing but that mark was on the other side of where the timing marks were at. So I guess that tells me that the ring on the balancer did slip. Am I right to assume that or does anyone have another explanation? I just want to make sure I replace/fix the right thing
Fleet Owner
Joined: Oct 2005
Posts: 20,789
Likes: 1,753
From: Kentucky
Once cleaned up apply some paint so you can see it easier.
Thread Starter
|
Freshman User
Joined: Sep 2014
Posts: 39
Likes: 0
I used a wire brush to clean the ring so I could see the markings. Afterwards I could see them much better, they were just not showing up when I used the timing light because of what I think was the balancer ring slipping. I was seeing a scratch on the ring that I thought was a timing mark but it actually was a scratch, just on the other side of the ring.
Thread Starter
|
Freshman User
Joined: Sep 2014
Posts: 39
Likes: 0
Odisvan,
Initially, the entire engine would shake/vibrate almost like something was off balance as the engine was running. It ran like this for a month or so as I was trying to figure out exactly what was going on. Then out of the blue I left it sitting over the weekend and cranked it up on Monday about 2 weeks ago and it ran fine for a few days and then got back to running like crap. I checked the timing today and I couldn’t even see the timing marks as the light was flashing on the ring.
Initially, the entire engine would shake/vibrate almost like something was off balance as the engine was running. It ran like this for a month or so as I was trying to figure out exactly what was going on. Then out of the blue I left it sitting over the weekend and cranked it up on Monday about 2 weeks ago and it ran fine for a few days and then got back to running like crap. I checked the timing today and I couldn’t even see the timing marks as the light was flashing on the ring.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Fleet Owner
Joined: Oct 2005
Posts: 20,789
Likes: 1,753
From: Kentucky
Based on your latest response and photos it appears the balancer has slipped. Why the vibration "went away" for a few days is anyone's guess. Now that you know there is a problem fix it. Then see if your vibration goes and stays away.
Elder User
Joined: Jul 2015
Posts: 730
Likes: 0
I’ve Only had one harmonic balancer to slip, n a Chevy 230 straight 6, but it didn’t vibrate. Just had to approximate timing by ear, couldn’t rely on the marks. Im sure had I ran it longer it might’ve got worse or flung and trashed stuff. Yanked that motor asap to install 350.
my point is, nothing would have made engine on and off smooth, as you state, because regardless of outer part slip, the actual timing itself isn’t moving. Only the time marks are. So, my point is, it sounds intermittent. So, it was runnIng horrible but healed itself over a weekend but is back to missing and runnng rough? But, maybe it will smooth out again? Doesn’t sound like timing. It doesn’t alter itself by balancer slip.
my point is, nothing would have made engine on and off smooth, as you state, because regardless of outer part slip, the actual timing itself isn’t moving. Only the time marks are. So, my point is, it sounds intermittent. So, it was runnIng horrible but healed itself over a weekend but is back to missing and runnng rough? But, maybe it will smooth out again? Doesn’t sound like timing. It doesn’t alter itself by balancer slip.
Elder User
Joined: Jul 2015
Posts: 730
Likes: 0
It is the healing itself part that is your real clue. Timing doesn’t move itself without gear or chain issues, and that doesn’t temporarily heal itself ether. That’s why it sounded weather and rain related and distributor cap leakage to Me. Like it dried out real good me weekend and it ran away great til another rain bout.
FTE Chapter Leader
Joined: May 2006
Posts: 12,342
Likes: 1,318
From: Central Mississippi
I'm going to strongly re-recommend that you verify slippage before changing out the 1 year only harmonic balancer only to find it still seems "out of balance".
Pull plug on #1 (front passenger side) finger on hole, bump or rotate manually.
Observe rotor & see if it points to #1 terminal as compression tries to blow your finger off spark plug hole.
If timing marks are not anywhere near pointer, great, change it.
If they are, you've got other problems.
Pull plug on #1 (front passenger side) finger on hole, bump or rotate manually.
Observe rotor & see if it points to #1 terminal as compression tries to blow your finger off spark plug hole.
If timing marks are not anywhere near pointer, great, change it.
If they are, you've got other problems.